Druid whirlwind question

OK, I'm stumped and don't know how to rule this. A 6th level druid can wild shape as a small air elemental. A small air elemental can create a whirlwind 10-20' tall. The diameter (at the top) of a whirlwind is half its height.

The text for the whirlwind ability indicates that it can pick up creatures smaller than the whirlwind size, NOT the size of the creature becoming the whirlwind.

I think that this is the key distinction. My question really is: can a small elemental with a whirlwind 20' tall pick up 1 or more medium creatures in its whirlwind?

I have searched and searched and can't seem to find a FAQ that answers this, so I ask the reddit opinion.

When you say catch, I assume you mean "pick up" ? So a small air elemental that's 10' across at the top of a 20' whirlwind could pick up a medium character or two? Now the player of the druid believes that the RAI is that a medium can only pick up a small or smaller, etc... but our rules lawyer is arguing that it's based on the size of the whirlwind not the creator Size.

That's what I'm inclined to rule in my game... is there any official ruling on this? I have seen so many arguments for both ways, and even on the Paizo boards nobody has stepped in with a FAQ clarification. :(

I saw a fun build where you cast call lightning and then enter the whirlwind. While the enemy is trapped inside you you call lightning down the whirlwind and since its a stormy effect it boosts the call lightning damage.

Pretty good indeed, and call lightning is only level 3 (CL5). However, can you be targeted and attacked when in whirlwind mode? I am a wizard with a familiar and he has trash AC but that could render him useful; was just wondering.

Can you help me find where it specifically states that? My problem is that the description indicates that the size varies and is decided by the creature, and the size category is specifically mentioned as vs the whirlwind, not the creator's size category.